DELAWARE TWP. – A day after a re-constructed bridge was announced as open to the public, it’s closed again.

The Rosemont-Raven Rock Road bridge “is being closed right now to all traffic as a precaution due to concerns raised by the contractor this evening,” the county Public Works Department said in an email shortly before 6 p.m. Tuesday.

“Our consultant will be on site tomorrow to evaluate the concerns. The detour will be the same as before.”

The span, originally built in 1878, is “probably the oldest bridge in the world still standing with Phoenix columns, definitely in the United States, says Tom Mathews, county director of Public Works. He explained that the Phoenix construction technique, patented in 1862 by Samuel Reeves of the Phoenix Iron Co. of Philadelphia, was a major innovation at the time.